The electrons in a cathode-ray tube are produced by?
...The electrons in a cathode-ray tube are produced by?
heating a metal filament.
ionization of the air
applying a magnetic field to the y-plates.
applying an electric field to the x-plates
Correct answer is A
No explanation has been provided for this answer.
The heat from the sun reaches the earth by the process ...
The diagram above represents a transverse travelling wave. Which two points are 180° out of phas...
Which of the following ammeters may be used to measure alternating currents? i. moving-coil ammet...
A 100 kg device is pulled up a plane inclined at 30° to the horizontal with a force of 1000 N. I...
Which of the following instruments produces sound by the vibration of air column? ...
The diagram above shows two capacitors P and Q of capacitance 5μF and 10μF. Find the charges s...
Which property of a wave remains constant when the wave travels from one medium into another? ...
In which of the following media would sound wave travel fastest? ...